Seachem Reef Builder Solution Dosing

[Steve and his Animals]

I've been toying around with creating a liquid solution of Seachem's Reef Builder for my Red Sea Doser instead of buying liquid additives. I tried dissolving a half-cup (8tbsp) in a gallon of RO water, but it never seemed to dissolve fully with constant mixing. I figure, no issue, just over saturated, so I added that solution to another 4 gallons of RO (so 8tbsp/5gal) and still, it is not fully dissolving. Is there something I'm not taking into account? I feel as though if I dilute too far the amount of liquid I would have to dose daily would be used up very quickly in my gallon reservoir. Anyone with experience making a solution like this?

 

[Randy Holmes-Farley Verified Community Expert]

I've been toying around with creating a liquid solution of Seachem's Reef Builder for my Red Sea Doser instead of buying liquid additives. I tried dissolving a half-cup (8tbsp) in a gallon of RO water, but it never seemed to dissolve fully with constant mixing. I figure, no issue, just over saturated, so I added that solution to another 4 gallons of RO (so 8tbsp/5gal) and still, it is not fully dissolving. Is there something I'm not taking into account? I feel as though if I dilute too far the amount of liquid I would have to dose daily would be used up very quickly in my gallon reservoir. Anyone with experience making a solution like this?

FWIW, Seachem does not state what the product is, but it will be mostly a mix of sodium bicarbonate and some sodium carbonate.

Sodium bicarbonate is less soluble than sodium carbonate, and solutions of it must be more dilute. I'm not sure why it isn't dissolving well when diluted more.

IMO, there's no reason to mess with Seachem for this need. Just using baking soda (sodium bicarboatne), or sodium carbonate (baked baking soda) and you will be good to go with a product of known purity (unlike the Seachem material).

Here are some recipes:

An Improved Do-it-Yourself Two-Part Calcium and Alkalinity Supplement System by Randy Holmes-Farley - Reefkeeping.com

 

[Steve and his Animals]

FWIW, Seachem does not state what the product is, but it will be mostly a mix of sodium bicarbonate and some sodium carbonate.

Sodium bicarbonate is less soluble than sodium carbonate, and solutions of it must be more dilute. I'm not sure why it isn't dissolving well when diluted more.

IMO, there's no reason to mess with Seachem for this need. Just using baking soda (sodium bicarboatne), or sodium carbonate (baked baking soda) and you will be good to go with a product of known purity (unlike the Seachem material).

Here are some recipes:

An Improved Do-it-Yourself Two-Part Calcium and Alkalinity Supplement System by Randy Holmes-Farley - Reefkeeping.com

Is there a benefit to mixing carbonate with bicarbonate? Why would seachem use a recipe like that?

 

[Randy Holmes-Farley Verified Community Expert]

Is there a benefit to mixing carbonate with bicarbonate? Why would seachem use a recipe like that?

It’s not generally an especially useful recipe, IMO, but there’s a kernel of truth that they use to mislead with the ridiculous claim that

“Reef Builder™ raises carbonate alkalinity (KH) without immediately impacting on pH. With long term use there will be a tendency to stabilize at pH 8.3.”

Bicarbonate has a tiny pH lowering effect when first added. Carbonate has a pH raising effect. A mix of the two can be devised that won’t raise or lower pH when added to seawater any that specific pH. For pH 8.3, that is mostly bicarbonate and done carbonate.

However, many people have low pH due to elevated indoor CO2, and a recipe like that does not help nearly as much as a pure carbonate version.

 

[Steve and his Animals]

It’s not generally an especially useful recipe, IMO, but there’s a kernel of truth that they use to mislead with the ridiculous claim that

“Reef Builder™ raises carbonate alkalinity (KH) without immediately impacting on pH. With long term use there will be a tendency to stabilize at pH 8.3.”

Bicarbonate has a tiny pH lowering effect when first added. Carbonate has a pH raising effect. A mix of the two can be devised that won’t raise or lower pH when added to seawater any that specific pH. For pH 8.3, that is mostly bicarbonate and done carbonate.

However, many people have low pH due to elevated indoor CO2, and a recipe like that does not help nearly as much as a pure carbonate version.

A higher KH has a direct increase on buffering capacity, that's how those compounds raise pH yes?

 

[Randy Holmes-Farley Verified Community Expert]

A higher KH has a direct increase on buffering capacity, that's how those compounds raise pH yes?

No. They raise pH by taking up CO2 as they are mostly converted from carbonate in the supplement to mostly bicarbonate in tank water:

CO3- - + CO2 + H2O —> 2HCO3-

 

[Steve and his Animals]

No. They raise pH by taking up CO2 as they are mostly converted from carbonate in the supplement to mostly bicarbonate in tank water:

CO3- - + CO2 + H2O —> 2HCO3-

That makes sense, thanks for the clarification

 

[Randy Holmes-Farley Verified Community Expert]

That makes sense, thanks for the clarification

You're welcome.

This article has a ton more info on that topic:

Chemistry And The Aquarium: The Relationship Between Alkalinity And pH ? Advanced Aquarist | Aquarist Magazine and Blog